Sensing and Defibrillation With a Commercially Available ICD Coupled With a Parasternal Extravascular Lead (SECURE EV) Study

Inclusion Criteria: 1. At least 18 years old 2. Indicated for de novo or replacement ICD procedure Exclusion Criteria: 1. NYHA IV functional class 2. BMI ≥ 35 kg/m2 3. Inotropic therapy in past 180 days 4. Subjects who require continual ventricular pacing 5. Presence or planned use of a subcutaneous ICD lead, subcutaneous coils/arrays, epicardial patches or epicardial pace/sense leads within the study period. 6. Planned MRI within the study period 7. Subjects on anticoagulation or antiplatelet therapy that cannot be temporarily discontinued for the procedure 8. Logistical or safety related circumstances that may prevent data collection or follow-up 9. Participation in any concurrent clinical study without prior written approval from the Sponsor 10. Inability to give an informed consent to participate in the Study Known prior history for any of the following: 11. Structural abnormalities of the heart that may increase risk of the study procedure or an obstructed/restricted pathway into the mediastinum for the EV-ICD Dilator, EV-ICD Delivery Tool and EV-ICD Lead 12. Uncontrolled paroxysmal, persistent or permanent atrial fibrillation 13. Median or partial sternotomy 14. Surgery with disruption of the lung, pericardium or connective tissue between the sternum and pericardium 15. Significant anatomic derangement of or within the thorax (e.g., pectus excavatum, significant scoliosis) 16. Thoracic radiation therapy, pneumothorax, pneumomediastinum or other medical treatments/conditions which may complicate the EV-ICD Lead insertion procedure 17. Pericardial disease, pericarditis and mediastinitis 18. Medical treatments, surgeries or conditions that increase the potential for pericardial adhesions 19. FEV1 \< 1.0 Liter 20. Surgically corrected congenital heart disease (not including catheter-based procedures) 21. Allergies to the device materials as listed in the Instructions for Use (IFU)